Ferrous base alloy for piercer points



Patented Aug. 9, 1949 UNITED STATES ATENT OFFICE.

N'o-D'rawing. Application November 29, 1946; Serial No. 713,106

K Claims. I.

This invention relatestoan alloy and more particularly to: an alloyfrom: which piercing points as used in seamless tube mills can be cast.

The-principal object of: the inventionis the provision of an alloyparticularly adapted for the formation of piercing points: for use inseamless tube mills, the piercing points: formed from the alloy being.characterized by their ability toform and maintain a nickel aluminumsurface oxida tion forming a protective sheath on the piercing pointwhen in operation.

A further object of the invention is the provision. of an alloy fromwhich: piercing points canbe cast and characterized in that the piercingpoints formed therefrom have an unusually high resistance to picking upparticles oi the metal being pierced.

A still further object of the invention is the provision of a steelalloy including effective quantities of nickel and aluminum from which:alloy piercing points for'seamlesstubemill use can ibe cast and whichalloy incast form is characterizedby the ability to forma; nickelaluminum surface oxide particularly advantageous as a lubricating.sheath when the piercing point is used in a piercing operation.

It is known that in the manufactureof pipes and tubes,.piercing. pointsare commonly used for piercing billets to form seamless pipe and tube.The various metals from which-seamlesspipe and tube are formed ofie'rconsiderableresistance to the iercing points used for piercing the sameand it is known. in this art that a relatively high failure ratio iscommon in connection with piercing points used in. piercing metalbilletsin forming the seamless pipe and tube.

An ideal piercing point for the formation of seamless pipe and tubewould be' capable of repeated operation without distortion of shape orpicking up particles of metal being pierced. The present inventionrelates to an alloy which appreaches this ideal inthat arelatively softsteel alloy is disclosed. which includes relatively high quantities ofnickel and aluminum and in amounts suflicient to characterize the alloyby its ability to form anickel aluminum oxidewhich forms a protectiveand lubricating coating on the piercing point during the piercing of albillet. The alloy is also capable of withstanding high thermal shockwithout deforming, cracking or otherwise becoming unsuitable for use,and, more importantly, is entirely free of any tendency toward pickingup particles of metal being pierced.

The alloy may be efliciently handled and formed into usable piercingpoints as by casting,

thereby making it a very satisfactory metal for this purpose as piercingpoints are commonly formed by casting. The several desirable quali tiesof the alloy herein disclosed make it highly desirable for use inpiercing alloy steels of the high chromium and high chromium nickeltypes.

The alloy disclosed herein including substantial quantities of nickeland aluminum possesses scaling properties far superior to alloys hereto?fore known in the art and used for the formation of piercing points forseamless tube mill use. Thesuperiority lies primarily in the ability ofthe alloy to form: a nickel aluminum surface oxide and to maintain atightly adhering nickel aluminum surface oxide over its entire surfaceduring operation, and further in the: fact that the nickel aluminumoxide fuses and melts during a piercing operation thereby forming adesir able lubricating and protecting sheath on the piercing point.

The piercing points formed of the alloy may be of various shapes andsizes known in the art and they may comprise, for example,- a pointpor-- tion, a tapered body portion and the usual sleeve or neck portionof a smaller diameter than the body portion, the whole of which isadapted for simple mounting on the end of the plug bar of a seamlesstube mill.

It is known that it hasb'een proposed to form steel alloys withrelatively minute quantities of aluminum and it is known that suchquantities of aluminum as have heretofore been incorporated in similaralloys have been entirely ineffective in the formation of a protectiveand lubricatingoxide on theformed' article.

In the present invention the substantial quantities of nickel andaluminum contribute to the successful formation of the protective oxidecoating Whichis so important in the piercing opera tion as it enablesthe piercing point to maintain its proper size and shape and thereby beefficiently used" in the" formation of satisfactory seamlesspipesandtubes.

The heretofore commonpractice in the formation' of alloys for piercingpoints has been to depend upon such alloying ingredients .as chromiumand copper to" form a soft steel in an attempt to" provide a piercingpoint which possesses satisfactory scaling properties. Such alloys,however, have generally been incapable of repeated use as the lack ofuniform scaling properties result in rapid distortion of the shape ofthe piercing points making the replacement necessary.

The various objects of the invention are achieved by the composition ofan alloy including about .20% to 1% carbon, molybdenum i effectivequantities up to 3.50%, 3% to 12% nickel, copper in effective quantitiesup to 7.50%, and effective amounts of aluminum up to 3%, about 25% to1.25% silicon, about 25% to 1.25% manganese, and vanadium in efiectivequantities up to 50%, and the remainder all iron. The silicon andmanganese are common in steel alloys and the alloy herein disclosedincludes the usual percentages of sulphur and phosphorus which are notobjectionable.

The alloy shown herein may be hardened if desired by the addition ofcobalt and/ or tungsten in amounts up to 5% of the alloy. The additionof the cobalt and/or tungsten in such amounts will be found to hardenthe alloy somewhat and affect the ability of the alloy to form theprotective and lubricating nickel aluminum oxide.

A typical heat of the steel alloy of my invention possessing the severalcharacteristics heretofore described may be seen in the followinganalysis: carbon 1%, molybdenum 75%, nickel 8%, copper 1.50%, aluminum3%, silicon 1.25%, manganese 1.25%, vanadium 50%, and the remaindersubstantially all iron. A steel alloy formed in accordance with thisinvention is of such nature as to lend itself particularly well to theformation of cast articles such as piercing points which may besuccessfully used as integral parts in seamless tube mill equipment. Itwill be observed that the alloy includes relatively high quantities ofnickel and aluminum. The amounts of the nickel and aluminum may bevaried between the minimum effective content and about 12% for thenickel and 3% for the aluminum.

It will be seen that the relatively high percentage of the nickel andaluminum alloying elements result in the alloys ability in cast form toresist pick up of metal of the billet being pierced as it forms aneiiective continuously replacing lubricating metallic coating.

It will thus be seen that the several objects of the invention areachieved by the provision of a castable steel alloy by includingrelatively high percentages of nickel and aluminum. The physicalcharacteristics 01 the alloy may be altered by heat treatment and thealloy may be hardened, if desired, by the addition of cobalt and/ ortungsten in amounts up to 5%.

Having thus described my invention, what I claim is:

1. A steel alloy having about 1% carbon, about .75% molybdenum, about 8%nickel, about 1.50% copper, about 3% aluminum, about 1.25% silicon,about 1.25% manganese, about .50% vanadium, and the remainder all ironand including the usual percentages of sulphur and phosphorus, the saidalloy being capable of being cast and being characterized by the abilityto form and retain a nickel aluminum oxide surface coating under severeheat and abrasion conditions.

2. A steel alloy having an analysis including between about .20% to 1%carbon, between about .75% to 3.50% molybdenum, between about 3% to 12%nickel, between about 1.50% to 7.50% copper, between about 2% to 3%aluminum, between about .25% to 1.25% silicon, between about 25% to1.25% manganese, between about 25% to 50% vanadium, and the remainderall iron and including the usual percentages of sulphur and phosphorus,the said alloy being capable of being cast and bein characterized by theability to form a nickel aluminum oxide and retain it under severe heatand abrasion conditions and the ability to retain its cast shape undersevere heat and abrasion conditions.

3. A steel alloy having an analysis including between about .20% to 1%carbon, between about .75% to 3.50% molybdenum, between about 3% to 12%nickel, between about 1.50% to 7.50% copper, between about 2% to 3%aluminum, between about 25% to 1.25% silicon, between about 25% to 1.25%manganese, between about 25% to 50% vanadium, between about 1% to 5%cobalt and the remainder all iron and including the usual percentages ofsulphur and phosphorus, the said alloy being capable of being cast andbeing characterized by the ability to form a nickel aluminum oxide andretain it under severe heat and abrasion conditions.

4. A steel alloy having an analysis including between about .20% to 1%carbon, between about .75% to 3.50% molybdenum, between about 3% to 12%nickel, between about 1.50% to 7.50% copper, between about 2% to 3%aluminum, between about 25% to 1.25% silicon, between about 25% to 1.25%manganese, between about 25% to 50% vanadium, between about 2% to 5%tungsten and the remainder all iron and including the usual percentagesof sulphur and phosphorus, the said alloy being capable of being castand bein characterized by the ability to form a nickel aluminum oxideand retain it under severe heat and abrasion conditions. a

5. A steel alloy having an analysis including between about .20% to 1%carbon, between about .75% to 3.50% molybdenum, between about 3% to 12%nickel, between about 1.50% to 7.50% copper, between about 2% to 3%aluminum, between about 25% to 1.25% silicon, between about 25% to 1.25%manganese, between about .25% to 50% vanadium and effective amounts ofcobalt and tungsten together totaling between about 2% to 5% and theremainder all iron and including the usual percentages of sulphur andphosphorus, the said alloy being capable of being cast and beingcharacterized by the ability to form a nickel aluminum oxide and retainit under severe heat and abrasion conditions.

JACOB TRANTIN, JR.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date ,649,398 Fry Nov. 15, 1927FOREIGN PATENTS Number Country Date 144,892 Austria Mar. 10, 1936

